Hypoparathyroidism (or Hypopara or HPTH for short) is a rare endocrine condition in which insufficient or inactive levels of parathyroid hormone (PTH) are produced by the parathyroid glands in your neck.

This leads to low calcium levels in your blood, a condition called hypocalcaemia which can be a serious condition if untreated.

Hypoparathyroidism is a rare endocrine condition

Endocrinology is the study of hormones and what they do

Hormones are chemical messengers released into the blood that cause changes in cells.

'Endocrinology is really very simple. You can have too much of a hormone … or too little'.*

In Hypoparathyroidism, you have too little parathyroid hormone.

What causes Hypoparathyroidism?

Hypoparathyroidism may be due to a congenital, genetic or autoimmune disorder which affects the function of the parathyroid glands or, more commonly, it may occur as the temporary or permanent result of surgery to the neck where there is removal of, or damage to, the glands.

Where are the parathyroid glands?

In your neck, just behind the butterfly shaped thyroid gland, lie the parathyroid glands. Sometimes they may also be found elsewhere in the body.

They are not related to the thyroid except by name - 'para' comes from the Greek for 'near'.

Shown here, these four tiny yellow glands are about the size of a grain of rice and play a vital role in the body.

What do the parathyroid glands do?

Calcium levels fluctuate constantly in response to a number of factors such as food, drink, exercise, stress, infection and other medications.

The role of the parathyroid glands is to regulate calcium levels and keep them stable. They do this by means of an automatic feedback system which continually monitors the amount of calcium in the blood as it flows through them and makes constant adjustments to keep the calcium levels stable.

How does this feedback mechanism work?

If calcium levels begin to fall the parathyroid glands respond by increasing their output of parathyroid hormone (PTH) into the blood.

This acts, along with calcitriol (vitamin D hormone), to send instructions to other parts of the body.

Three way action is then taken:

the bones release more calcium into the blood

the intestines absorb more calcium from food

the kidneys reduce the calcium and increase the phosphate we excrete in our urine.

As calcium levels begin to rise this process works in reverse by decreasing the parathyroid hormone output so that calcium levels start to fall again.

This amazing feedback mechanism goes on all the time, day in, day out, to prevent calcium levels from getting out of control.

In Hypoparathyroidism, that mechanism is broken so getting the right amount of calcium becomes much more difficult. We have to rely on medication, blood tests and a certain amount of guesswork to keep the calcium level stable.

What happens if my parathyroid hormone level is low?

Low levels of parathyroid hormone (PTH) in the blood affect other levels and will cause:

low levels of calcium

low levels of calcitriol (active vitamin D)

high levels of phosphate

It also means that these levels cannot be regulated automatically by the parathyroid glands, as happens normally.

How does this affect me?

There are no symptoms caused by low PTH levels, only by unstable calcium levels. You may have very few symptoms or you may experience more severe symptoms. Low calcium levels (hypocalcaemia) and high calcium levels (hypercalcaemia) may be felt both physically, emotionally and neurologically.

High levels of phosphate may cause problems in the long term. This can lead to kidney stones and sometimes kidney damage.

Why is calcium so important?

Calcium is vital to life and affects every cell in the body. Most people know about teeth and nails in connection with calcium but in fact its effects are on the whole body. Calcium works with phosphorous to produce energy within the body. It helps blood to clot and is important in the correct functioning of nerves and muscles as well as the kidneys, eyes, bones and heart. Calcium is crucial to us which is why the body has special mechanisms in place to keep calcium levels constant.

How is Hypoparathyroidism diagnosed?

Diagnosis is by blood tests. In Hypoparathyroidism, blood calcium level is low, blood phosphate level is high, and parathyroid hormone level is low. If tests show these results, you will be referred to an endocrinologist at your local hospital.

Can I do anything to help myself?

Yes, you can! Learning how to recognise your symptoms can help you manage your condition and understand when your medication may need to be adjusted. There are other things you can learn about too. As a member of HPTH UK you can join our forum where we can help you to manage your levels and there is always someone around to answer your questions. You can also take a look at our members' pages, especially the Self Help Guide.

Quick Facts: Hypoparathyroidism (Hypopara or HPTH) is a rare endocrine disorder which can affect all ages. There are several forms - people may be born with it or inherit it but, most commonly, it is caused by damage sustained during surgery to the neck.

It causes low levels of parathyroid hormone which lead to low calcium levels in the blood. Calcium is vital to life. Unlike diabetics, but despite very similar difficulties, HPTH patients have neither replacement hormone therapy nor home testers available to help them manage this difficult condition. More info